1. Field of the Invention
The present invention relates to an image acquisition system including an image acquisition device and a commanding device configured as a unit separate from the image acquisition device proper and a method of authenticating the image acquisition device in the image acquisition system.
2. Description of the Related Art
In recent years, concern about the protection of personal information and information security has become so high that, from the viewpoint of protection of personal information and privacy, even an image acquired by oneself must be carefully handled in an increased number of cases depending on the image contents, especially in the case where an image of another person is included.
In a conventional 35-mm film camera, the number of frames is 24 to 36, and should a camera loaded with a film of 36 frames imaged be lost or stolen, at most 36 images lost, this being a relatively small number compared with a digital camera. Depending on the contents, the less would of course be great and so would be the risk of the information leakage.
With the advent of the age of the digital camera, on the other hand, the acquired images are recorded in the internal memory of the camera as digital information. The images thus recorded can be easily copied on the one hand, and even if they are copied without permission of the owner, the original images remain as they are, and therefore, the owner may not be aware that the images have been copied on the other hand.
Recently, the storage capacity of the storage medium of the digital camera has been so increased that the memory card of even 4 gigabytes is now placed on the market. In the semiconductor market, Moor's Law is known, according to which the design rule is decreased from 90 to 65 mm and further to as small as 45 mm. In the future, the storage capacity of the semiconductor memory continues to be in upward tendency. The capacity of the compact hard disk is also on the increase, and even the hard disk in the size of a Compact Flash (registered trademark) card has reached several gigabytes in capacity. This tendency is expected to continue in the future.
In the case where the storage capacity per frame of image is one megabyte on the average, for example, 2000 frames of images can be recorded in the memory card of 2 gigabytes, and 6000 frames of images in the hard disk of 6 gigabytes. Under the circumstances, an enormous amount of personal information beyond comparison with the storage capacity for the film camera is now carried with each camera.
The image is recorded in the digital camera with the image acquisition date, etc. Some cameras can record even positional information by GPS. In other words, privacy information such as the behavior and the relationships of individual persons are stored in a great amount as images and data. If the camera is lost, a similar camera can be repurchased at several ten to several hundred thousand yen, but the lost images and information may invite the risk of a greater loss.
The image recording format of the digital camera is standardized, and by removing a removable memory card or a card-type hard disk from the camera and inserting it into the memory slot of the card reader or the personal computer (hereinafter sometimes referred to simply as PC), the images and the accompanying information can be easily viewed or copied.
With the increased memory capacity and the decreased price as a background, even a camera with a nonreplicable built-in memory of about 16 megabytes has appeared, with which images can still be recorded even if the removable memory is full or not installed. In view of this situation, a method has been realized to improve the security by increasing the capacity of the built-in memory and preventing the reproduction of the images from the built-in memory without meeting specified conditions, while at the same time making the conventional removable memory compatible with other cameras.
A considerable number of methods have so far been proposed to improve the security by prohibiting the use of the camera by other than the owner and thus preventing the information leakage and the illegal use.
According to EP 1003069 A2, for example, the ID information of the user is registered, and by reading and collating in advance, the use is permitted only in the case where the ID is coincident. Specifically, the function of verifying the retina pattern, the fingerprint or the voiceprint has been proposed. Also, a method has been proposed in which the ID information is input in the memory card in advance and required to be read. In still another method proposed, a keyboard is provided as an ID input unit to input the ID number.
On the other hand, US 2005/0001024 A1 proposes that a first electronic device held by the user and having stored the personal information of the user communicates with a second electronic device by radio, and the second electronic device is customized in accordance with the user by automatically reading the personal information of the particular user.
Further, Jpn. Pat. Appln. KOKAI Publication No. 2005-42398 proposes a car garage shutter system in which the identification data is stored in a remote controller. The use of a private key as the authentication information or the encrypted information has been proposed. The authentication of voice, iris or fingerprints has also been proposed.
To maintain the security of the information, devices and system, on the other hand, an electronic certificate based on a public key and the one-time password utilizing an authentication server and a network also find practical application as a method high in security.